add a costume thanks button..rather than Thanks word

[Cleopatra]

Ok
I have installed a thanks for posts mod
It works great
But the problem is
That the
Thanks word
Doesn't have a button so it appear as a word
I have asked my gfx designer to make me one on gif extension
He did
And when I tried to add it via FTP to my
Images/my theme/English..
I named it both
Thanks.gif
And
Postbit_thanks.gif

But still the button appears as a Thanks word
Not button
Can anybody help me